usb: host: xhci-plat: Create platform device for onboard hubs in probe()

Check during probe() if a hub supported by the onboard_usb_hub
driver is connected to the controller. If such a hub is found
create the corresponding platform device. This requires the
device tree to have a node for the hub with its vendor and
product id (which is not common for USB devices). Further the
platform device is only created when CONFIG_USB_ONBOARD_HUB=y/m.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>

drivers/usb/host/Kconfig

@@ -54,6 +54,7 @@ config USB_XHCI_PCI_RENESAS
 config USB_XHCI_PLATFORM
 	tristate "Generic xHCI driver for a platform device"
 	select USB_XHCI_RCAR if ARCH_RENESAS
+	depends on USB_ONBOARD_HUB || !USB_ONBOARD_HUB
 	help
 	  Adds an xHCI host driver for a generic platform device, which
 	  provides a memory space and an irq.

drivers/usb/host/xhci-plat.c

@@ -15,6 +15,7 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/usb/onboard_hub.h>
 #include <linux/usb/phy.h>
 #include <linux/slab.h>
 #include <linux/acpi.h>
@@ -195,6 +196,7 @@ static int xhci_plat_probe(struct platform_device *pdev)
 	int			ret;
 	int			irq;
 	struct xhci_plat_priv	*priv = NULL;
+	struct device_node	*np;
 
 
 	if (usb_disabled())
@@ -374,6 +376,17 @@ static int xhci_plat_probe(struct platform_device *pdev)
 	 */
 	pm_runtime_forbid(&pdev->dev);
 
+	np = usb_of_get_device_node(hcd->self.root_hub, hcd->self.busnum);
+	if (np && of_is_onboard_usb_hub(np)) {
+		struct platform_device *pdev;
+
+		pdev = of_platform_device_create(np, NULL, NULL);
+		if (pdev)
+			hcd->onboard_hub_dev = &pdev->dev;
+		else
+			xhci_warn(xhci, "failed to create onboard hub platform device\n");
+	}
+
 	return 0;
 
 
@@ -420,6 +433,9 @@ static int xhci_plat_remove(struct platform_device *dev)
 	usb_remove_hcd(hcd);
 	usb_put_hcd(shared_hcd);
 
+	if (hcd->onboard_hub_dev)
+		of_platform_device_destroy(hcd->onboard_hub_dev, NULL);
+
 	clk_disable_unprepare(clk);
 	clk_disable_unprepare(reg_clk);
 	usb_put_hcd(hcd);

include/linux/usb/hcd.h

@@ -225,6 +225,8 @@ struct usb_hcd {
 	 * (ohci 32, uhci 1024, ehci 256/512/1024).
 	 */
 
+	struct device *onboard_hub_dev;
+
 	/* The HC driver's private data is stored at the end of
 	 * this structure.
 	 */